Method of and apparatus for feeding webs or strips



g- 8, 1933- K. 8. SMITH 1,921,487

METHOD OF AND APPARATUS FOR FEEDING WEBS OR STRIPS Filed Sept. 24, 19502 Sheets-Sheet 1 -f 1933- K. s. SMITH 1,921,487

METHOD OF AND APPARATUS FOR FEEDING WEBS OR STRIPS I Filed Sept. 24,1930 2 Sheets-Sheet 2 Jwuentoc Lien/n6 ih AS. b'rniih,

Patented Aug. 8, 1933 UNITED STATES METHOD OF AND APPARATUS FOR FEED-ING WEBS OR STRIPS Kenneth Stuart Smith, West Wimbledon, Eng land,as'signor to Eastman Kodak Company, Rochester, N. Y., a Corporation ofNew York Application September 24,1930, Serial No. 484,222, and in GreatBritain November 13, 1929.

6 -Clairns.- o1. 271-2.2

This invention relates to the feeding of webs or strips of flexiblematerial such as woven fabrics, paper, celluloid film or the like andhas for its chief object to provide an improved method and apparatus forfeeding such webs or strips through a liquid without subjecting them toexcessive tension. Y

It is often necessary in connection with the manufacture or treatment oflong bands of relatively delicate material such as paper, woven fabric,celluloid film or the like to pass the band relatively slowly throughone or more chambers in which the band is subjected to thesection of aliquid as for example when the band is first coated with some substanceor impregnated with a solution and subsequently permitted to dry'beforebeing cut off in short lengths or wound upon a take-up roller.

Insuch case the band is as a rule made to assume a number of loops, theupper end of each loop being passed over a roller which is positivelydriven to impart the necessary feed to the strip without subjecting thewhole length of the strip to tension. Such a feed mechanism isnecessarily complicated and this is particularly the case where the bandunder treatment is for the main part immersed in a solution, as in thecase of photographic film which is undergoing the process ofdevelopment, fixing, washing etc.

According to this invention the method of feeding a web or strip offlexible material in a series of loops through a liquid withoutsubjecting the total length of all the loops to tension. consists insuccessively extending certain loops. for example alternate loops. andin maintaining suificient tension in the length of material between thelast loop and the final winding reel or its equivalent to take up theslack which is thus intermittently formed between them.

The upper and lower end of each loop is sup ported upon a frame orstrainer so that the Whole loop can be extended or shortened when theframe is moved.

The apparatus by which the method is carried out conveniently comprisesa number of similar frames including a plurality of movable assemblieshaving transverse rollers at the upper ends of the frames and includinga plurality of rollers mounted in alignment with the rollers of themovable assembly to form the lower ends of the frames. An actuatingmeans alternately moves alternate movable assemblies so that the loopsare alternately extended and shortened. The web is then conducted to aweb receiving means which includes a take-up roll frictionally driven totake up the slack in the last loop only and a ratchet mechanismpreventing reverse rotation of the take-up roll. The frictional drivefor the take-up roll does not have sufiicient driving power to draw theweb through the loops with consequent increasing tensions in the loops.

The invention is particularly applicable to the development of aphotographic film other than cinema or like film having perforatedmargin,

and one form of apparatus embodying the invendeveloping, rinsing, fixingand washing the film,

and a chamber A in which the film is finally dried as by directing acurrent of warm air upwards through a conduit A Rotatably mounted inbearings B above the tanks is a camshaft B,

a similar camshaft B being mounted in bearings B above the dryingchamber A. The camshafts B, B which can be simultaneously driven by amotor C through chain or belt gear C are provided with a number of camsB (Figure 2) and similar straining frames are arranged side by side inthe tanks and the drying chamber, each cam cooperating with the movableassembly of each frame. The cams are so set that when the camshafts B, Bare rotated by the motor C, the upper movable assembly,broadlydesignated as D,

of each alternate frame or group of frames is raised whilst the similarparts of intermediate frames are simultaneously lowered.

The cams B are preferably circular and are eccentrically mounted inaxial spacial relation on shaft B. The greatest eccentricities ormaximum portions of alternate cams B are in the same position or inalignment along shaft B. Also the maximum portions of adjacent cams Bare 180 displaced from each other on shaft B. Thus the movableassemblies D are alternately moved from lowermost to uppermost positionsor vice versa during 180 revolution of shaft B.

One construction of the straining frame for dealing with two stripssimultaneously is'illustrated in Figure 2 and comprises two verticaltubular guide members D normally fixed to the tank by means ofhorizontal arms D Mounted to reciprocate in these normally fixed guidesis -a movable assembly D comprising parallel plungers D connected by atransverse rod D carrying a central roller D Freely rotatable on theouter ends of the transverse rod D are two rollers E, two similarrollers E being rotatably carried on spindles E at the lower end of thefixed guides. The rotation of the camshaft results in the cam B engagingthe roller D and thereby moving the transverse rod and the rollers Eupwards against the action of springs D The upper and lower rollers E, Eon each straining frame are in vertical alignment and the arms D are soarranged that any one straining frame can be bodily removed from thetank Without interfering with the straining frames on eithersidethereof. The straining frames provided in the drying chamber A are, inthe construction illustrated in Figure 1, shown as permanently fixedrelatively to the chamber, the lower portion of the tubular members Dbeing in this case omitted and the lower rollers of each frame carriedon fixed spindles.

The strip of film F--which may be made by suitably securing together anumber of relatively short lengths of the same or different widthis ledfrom a roller F to a gravity tension device F and thence over the upperroller E of the first frame in the developing tank A as shown inFigure 1. The film is then led downwards and slightly backwards so as topass under the corresponding roller E at the lower end of the same framebefore being led up again to the upper roller ofthe next frame. The filmis led in this manner over the frames in the remaining tanks and thedrying chamber and finally to a winding-on or take-up reel G. The reel Gis driven from the camshaft B through a friction drive (not shown) whichmaintains a definite tension in the final strip or length between thelast roller E and the take-up reel G. A ratchet and pawl mechanism Gprevents reverse or unwinding rotation of roll G.

When the motor C is set in motion the cams B raise and lower alternatemovable assemblies D in each straining frame so that alternate loops ofthe film are extended whilst the intermediate loops are shortened,except where a junction occurs between the tanks when the two framesadjacent to this junction are made to move simultaneously and notalternately. Thus the slack of film produced by one loop which has justbeen extended is taken up and thereby transferred to the next loop bythe ascending movable assembly D. In this manner the slack is in turnpassed down the whole series of loops until it is wound on the take-upreel G.

The rollers E, E are of hour-glass shape as shown so as to accommodate afilm of varying width and, as the rollers are free to revolve upon theirspindles, any relative movement between the film and the rollers andconsequent damage to the film is prevented. The tanks are convenientlywholly or partially sunk so that the upper end of each loop is at aconvenient level for manipulation and inspection and if desired ahorizontal bar or the like may be provided above the tanks so that anyselected straining frame with the loop of film it carries can besuspended as, for example, when the tank is emptied or cleaned out.

The drying chamber may be of some known type and instead of the warm airbeing directed upward through the conduit A a fan may be disposed in theupper wall of the chamber above an elastic heater so arranged that warmair gently descends through the drying chamber in which the film, afterbeing washed, is slowly fed in loop formation as above described.

The web receiving means may be capable of adjustment to vary theeffective take-up of the reel G whereby the length of time for which thefilm is subjected to treatment in the tanks and in the drying chambercan be adjusted as desired.

It will be appreciated that the arrangement may be such that a singlecam-shaft operates all the movable assemblies both in the tanks anddrying chamber and that instead of alternate assemblies D being raisedand lowered the cams may be set to move the assemblies D in any otherdesired sequence, the setting and/ or shape of the cams being variedaccordingly. Further, instead of the film being wound upon a reel whichis frictionally driven and associated with a ratchet or likeuni-directional device, the film, after being dried, can be passedbetween two rollers by which it is gripped prior to being cut off orconveyed elsewhere. Although the invention has been described withparticular reference to the developing, fixing, washing and drying ofphotographic film, it is equally applicable to all cases in which a webof paper, fabric or other relatively fragile strip material is subjectedto the action of a liquid as it is gradually fed through one or morechambers.

Having now particularly described and ascertained the nature of myinvention and in what manner the same is to be performed, I declare thatwhat I claim is:--

1. A method of advancing a web of flexible material which comprisesforming the web into a plurality of loops, alternately extending andshortening alternate loops of the web with respect to each other andwinding up one end of the web at a definite tension sufficient to takeup the slack in the last loop only, whereby the web is intermittentlyadvanced.

2. A method of advancing a web of flexible material, which comprisesforming the web into a plurality of vertical loops, alternately raisingand lowering alternate loops and winding up the web at a tensionsufiicient to take up the slack in the last loop but not great enough todraw the web through the other loops whereby the web is intermittentlyadvanced.

3. In an apparatus for advancing a web of flexible material, the'combination with a plurality of frames adapted to conduct the web in aplurality of loops through the apparatus, each frame including astationary roller and a movable assembly having a roller, of anactuating means for alternately moving the alternate movable assemblieswith respect to each other and including a cam shaft and a plurality ofaxially spaced cams thereon, said cams being timed to reciprocate saidmovable assemblies alternately with respect to each other, and a webreceiving means including a roll frictionally driven and adapted to takeup the slack only in the adjacent loop.

4. In an apparatus for advancing a web of fiexible material, thecombination with a plurality of frames adapted to conduct the web in aplurality of loops through the apparatus, each frame including astationary roller and a movable assembly having a roller, of anactuating means for alternately moving the alternate movable assemblieswith respect to each other and including a cam shaft and circular camseccentrically mounted in axial spaced relation on said cam shaft and inoperative relation to respective movable assemblies and a web receivingmeans including a roll frictionally driven and adapted to take up theslack only in the last loop.

5. In an apparatus for advancing a web of flexible material, thecombination with a plurality of frames adapted to conduct the web in aplurality of loops through the apparatus, each frame including astationary roller and a movable assembly having a roller, 0! anactuating means for alternately moving the alternate movable assemblieswith respect to each other and including a cam shaft and circular camseccentri-' cally mounted in axial spaced relation on said cam shaft andin operative relation to respective movable assemblies, alternate camshaving the maximum portions thereof aligned and displaced 180 from themaximum portions 01' the adjacent cams, and a web receiving meansincluding a roll frictionally driven and adapted to take up the slackonly in the last loop.

shaft and a plurality of cams axially spaced on,

said shaft, in operative relation to each movable assembly and adaptedto raise alternate assemblies against the action of said springs and aweb receiving means including a roll frictionally driven and adapted totake up the slack only in the last loop.

KENNE'I'H STUART SMITH.

